Training swimming issue in 970 (TrainingPeaks)

In TP app I have configured swimming pool training

As we see I have few diffrent part of interwals. 

Sometimes Garmin watch is skipping whole interval or only "Rest". This looks randomly. I checked training using button lap before training is this looks ok.

In that training prblem was was on 6x50 (first interval was skipped) We have 1,2,4 without 3

and in 6x200 where last interval was skipped adn we see order of interval is strange: 12,13,18,15,16.

I have disabled option Auto Retst. Only what I have enabled is "Motion Detection"